Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C201/00—Preparation of esters of nitric or nitrous acid or of compounds containing nitro or nitroso groups bound to a carbon skeleton
  • C07C201/06—Preparation of nitro compounds
  • C07C201/12—Preparation of nitro compounds by reactions not involving the formation of nitro groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
  • C07C213/02—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton by reactions involving the formation of amino groups from compounds containing hydroxy groups or etherified or esterified hydroxy groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C231/00—Preparation of carboxylic acid amides
  • C07C231/12—Preparation of carboxylic acid amides by reactions not involving the formation of carboxamide groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C253/00—Preparation of carboxylic acid nitriles
  • C07C253/30—Preparation of carboxylic acid nitriles by reactions not involving the formation of cyano groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C315/00—Preparation of sulfones; Preparation of sulfoxides
  • C07C315/04—Preparation of sulfones; Preparation of sulfoxides by reactions not involving the formation of sulfone or sulfoxide groups

Definitions

• This invention concerns the manufacture of aryl esters having different substituents on the two aromatic rings.
• the diphenylether derivatives when substituted with functional groups, are industrial products of particular interest in the plastics industry; particularly, they take part in the manufacture of thermostable materials.
• Other functionalized compounds are intermediates for insecticides of very high efficiency.
• German Pat. No. 1 290 148 and No. 2 104 201 describe a new reaction for the production of diphenylethers substituted with electron attracting groups; the results of these works have been again published by H. Witt, G. Holtschmidt and E. Muller (Angew. Chem. Internat. Edit. 9, 1970 (1) p. 67).
• the process is based on the thermal decomposition with base catalysis of the corresponding phenyl carbonates. This process has the advantage of making use of a single starting product, the substituted phenol, and of making it possible to follow the course of the extent of reaction, which occurs in bulk, by the carbon dioxide evolution.
• This process is particularly adapted to the synthesis of diphenylethers substituted on each phenyl ring with identical electron attracting groups such as CN, NO 2 , carboxylic ester or phenylsulfone, but it does not solve the problem of synthesizing diphenylether derivatives substituted with two different electron attracting groups and these products may constitute highly desirable raw materials for manufacturing plastic materials.
• the object of the invention is to provide a process for manufacturing aryl ethers of the general formula
• the process of the invention generally consists of heating together, as a molten mass or as a solution, substantially equimolecular amounts of two aryl carbonates, each of which is di-substituted in a symmetrical manner, and complying respectively with the general formulae:
• the invention provides a process for manufacturing, with high yields, asymmetrical aryl ethers complying with the general formula
• Ar and Ar' are each a divalent aromatic radical comprising one or more rings (derived for example from benzene, naphthalene or anthracene, preferably a phenylene radical),
• X and Y are each an atom or group of substantial electron attracting character when bonded to the aromatic radical and are different from each other by their nature and/or by their respective positions on the radicals Ar and Ar', at least one and preferably the two substituents X and Y being so placed on the radicals Ar and Ar' as to have an action on the bond with the oxygen atom, i.e. in 2 (ortho) or 4 (para) position, or still in peri position when the considered radical (Ar or Ar') contains at least two fused rings.
• the involved electron attracting groups be not sensitive to the action of the bases.
• the electron attracting substituents X and Y are more particularly selected from --NO 2 ,--CN, --COO Ar", --SO 2 Ar” (wherein Ar” is a monovalent aromatic radical) and --CONR 1 R 2 groups (R 1 and R 2 being each a hydrogen atom or an alkyl group of 1 to 10 carbon atoms).
• Ar is a monovalent aromatic radical
• R 1 and R 2 being each a hydrogen atom or an alkyl group of 1 to 10 carbon atoms.
• one of the substituents, for example X is a --NO 2 group, the other, Y, being optionally selected from the above-mentioned groups.
• the process of the invention comprises heating, for example at a temperature from 190° to 280° C., substantially equimolecular amounts of the two aryl carbonates, each symmetrically substituted, and complying with the general formulas
• Ar, Ar', X and Y are defined as above, in the presence of a basic catalyst, consisting in particular of a salt of an alkali metal, for example a carbonate, a phenate, an acetate or an alcoholate. In most cases potassium carbonate is used.
• the catalyst amount is from 0.1 to 5 moles per 100 moles of the starting carbonates.
• the reaction may take place between the two aryl carbonates in a molten state (in bulk) or as a solution in an organic solvent such, for example, as nitrotoluene or acetonitrile.
• the symmetrically substituted aryl carbonates may be obtained from the corresponding phenols by any known method.
• Typical symmetrically substituted aryl carbonates which can be reacted with each other according to the process of the invention are:
• one of the involved aryl carbonates for example X--Ar--O--CO--Ar--X, is symmetrically substituted by two nitro groups in position 2 or in position 4.
• bis(4-nitrophenyl)carbonate is used.
• the second carbonate Y--Ar'--O--CO--O--Ar'--Y may then be specifically bis(3-nitrophenyl)carbonate, bis(4-cyanophenyl)carbonate, bis(2-phenoxy-carboxyphenyl)carbonate or bis(4-phenylsulfonyl-phenyl)carbonate, already mentioned above.
• the decarboxylation reaction preferably catalyzed by potassium carbonate, gives high selectivities and high yields, for example at least about 75% with respect to the starting carbonates.
• the asymmetrical aryl ethers obtained with good yields by the process of the invention, are industrial products particularly useful in the plastic materials industry, mainly for manufacturing certain thermostable materials.
• the aryl ethers substituted with one or more nitro groups may be subjected to a hydrogenation treatment, so as to convert the nitro group(s) to primary amine(s) groups.
• thermostable polymers by polycondensation with themselves (this is the case, for example, of the autocondensation of 2-(4'-aminophenoxy)phenyl benzoate) or with suitable antagonistic reactants having primary amine groups, hydroxy groups and/or monocarboxylic groups (acids or esters) or dicarboxylic groups (anhydrides, hemiesters and vicinal diesters). From these various reactants it is possible to prepare polycondensates containing esters or amides linkages or still heterocyclic linkages, particularly imides or quinazolones rings.
• a mixture of bis(2-phenoxy-carboxy phenyl)carbonate (9.1 g, i.e. 0.02 mole) and bis(4-nitrophenyl)carbonate (6.1 g, i.e. 0.02 mole) is heated to 240° C. in the presence of 0.1 g (0.0007 mole) of K 2 CO 3 .
• the reaction is very fast and 960 cm 3 (0.04 mole) of CO 2 at 20° C., corresponding to the theoretical amount, are recovered in less than 15 mn.
• the mixture is allowed to cool 80 cm 3 of a toluene-ethanol mixture (50/50 V/V) are introduced and brought to reflux. After hot filtration and cooling, a product crystallizes. It is filtered and dried under vacuum.
• a product which is phenyl 2-(4'-nitrophenoxy)benzoate is obtained in an amount of 10.3 g (yield 77% m.p. 139° C.).
• an additional amount of 1.6 g is obtained, so that the total yield of phenyl 2-(4'nitrophenoxy) benzoate reaches 89%.
• substituents were of the same nature on both carbonates but in different positions, meta position with respect to the oxygen atom bond on one of them and para position on the other.
• a mixture of bis(4-chlorophenyl)carbonate (5.7 g, i.e. 0.02 mole) with bis(4-nitrophenyl)carbonate (6.1 g, i.e. 0.02 mole) and K 2 CO 3 (0.2 g, i.e. 0.0014 mole) is heated to 240° C. for 4 hours. 400 cm 3 of CO 2 (i.e. about 0.017 mole) are recovered. At the end and after cooling 10 cm 3 of a concentrated ammonia solution and 40 cm 3 of dichloromethane are introduced. After 10 mn, 20 cm 3 of a cold 5% sodium hydroxide are added. The organic phase is settled, dried and evaporated.
• a mixture of bis(3,4-di-methoxycarbonylphenyl)carbonate (6.9 g, i.e. 0.0155 mole) with bis(4-nitrophenyl)carbonate (4.7 g, i.e. 0.0155 mole) and potassium carbonate (0.1 g, i.e. 0.0007 mole) is heated to 240° C. for a period of 20 mm, at the end of which the expected CO 2 theoretical amount is reached (750 cm 3 , i.e. 0.032 mole).
• the raw reaction product is dissolved into 50 cm 3 of dichloromethane and a preparative chromatography over silica provides 1.7 g of nitroanisole (0.011 mole), 0.8 g of bis(4-nitrophenyl)ether (0.003 mole) and 2.9 g of a substantially 50/50 mixture of methyl 4-(4'-nitrophenoxy)orthophthalate with methyl 4,4'oxy di-orthophthalate.
• the yield of dissymmetrical ether is only 14%.
• the operating conditions are those described in example 1, except that 0.2 g of potassium acetate (i.e. 0.002 mole) is used instead of the potassium carbonate.
• This Table shows the importance of the presence of electron attracting groups on both rings (compare Examples 1, 3, 4, 6 to Example 5 where one of the two rings is substituted with a chlorine atom).
• the Table also makes apparent the importance of the selection of the electron attracting groups, which must not be sensitive to the action of bases (compare Example 1, where one of the rings is substituted by a phenyl ester, to Example 2, where the substituent is a methyl ester and to Example 7, where the substituent consist of 2 methyl ester groups).

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• 1982
  • 1982-04-09 FR FR8206379A patent/FR2524879A1/fr active Granted
• 1983
  • 1983-03-28 DE DE8383400636T patent/DE3362150D1/de not_active Expired
  • 1983-03-28 EP EP83400636A patent/EP0091851B1/fr not_active Expired
  • 1983-04-08 US US06/483,316 patent/US4596680A/en not_active Expired - Lifetime
  • 1983-04-08 JP JP58062898A patent/JPS58192844A/ja active Pending

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